Role of Different Types of Polyacrylic Polymers on Decreasing the Ulcerogenic Effect of Certain Non-Steroidal Anti-inflammatory Drugs

Flunoxaprofen (FLP) and piroxicam (PIM), acidic non-steroidal anti-inflammatory drugs (NSAIDs), as well as floctafenine (FLN), basic NSAIDs, were coated with anionic and cationic polyacrylic resins adopting the fluidized bed technique. The bioavailability of the uncoated and coated drugs as well as the effect of the coat on the histopathological features of gastric mucosa were determined using male albino rats. Coating the particles largely affected the drug bioavailability as reflected on the peak heights, peak times and AUC0-24. FLP coated with cationic polymer showed increase in the peak height from 140.61 (uncoated drug) to 160.70 µg/ml. Peak time decreased from 4 hrs. to 2 hrs. AUC 0-24 increased from 2306.51 to 2835.21 µg/ml. hrs. The same parameters of the other two drugs PIM and FLN showed different behaviors according to their physicochemical characteristics as well as the nature of the coating polymer.

Different histopathological changes were observed in animals' stomachs which ranged between: no effect, deficiency of epithelial cells, necrosis, degeneration and hemorrhage. The changes were observed in rats administered PIM daily for 30 days as well as those administered FLP and FLN in single doses. Drugs coated with Eudragit-E100 showed significant decrease in ulcers obtained with uncoated drugs or drugs coated with the anionic type.